Discovering the Virtues of Networked Storage
In recent years, Scott County, Minnesota, has moved from direct-attached storage (DAS) to a virtualized IT infrastructure and storage area network (SAN) based on VMware and Compellent Technologies' Storage Center, and the county is just beginning to discover what its new infrastructure can do.
With about 90,000 residents and climbing, Scott County is one of the fastest-growing counties in Minnesota and the U.S. County officials turned to Compellent when they needed a storage solution that was flexible and offered good performance and room for growth.
"We began to virtualize our environment relying on direct-attached storage, but ultimately we knew that in order to take advantage of our VMware, it required a back-end SAN to house the data," says Todd Croy, infrastructure manager for Scott County in Shakopee, Minnesota.
Today, Scott County has two Storage Center systems, one configured with Fibre Channel drives that sit in the data center, and a second system, with SATA drives, that's located 14 miles away at the county's disaster recovery site in Jordan.
"We now have manageability of our data, disaster recovery, and the ability to expand our storage as needed," says Croy.
Not only has Scott County put all of its land records and birth certificates on the SAN, with plans to move additional county data to the SAN, it also relies on Storage Center to replicate VMware instances off site for disaster recovery of critical county data such as 911 dispatch call recordings, information from the criminal courts and driver's license information.
Just a few years ago, Scott County had about 25 servers, file servers with user data, SQL servers and Exchange servers, for example, all with direct-attached storage (DAS). The problem was that despite the fact that the servers each had 300GB to 400GB worth of storage, about half of it wasn't being utilized.
"Not only that, but we were managing the storage on a server by server basis," says Croy.
The county had also recently implemented VMware's ESX Server. "We started with one ESX server running seven virtual servers and ran it on the local storage of the server," he says.
The set up worked for a while, but then the county wanted to expand its virtualized environment. "That's when knew we needed a back-end SAN to house our data," says Croy. Disaster recovery was also very important to the county and backing up data in the existing environment was too troublesome.
The county looked at and tested SAN products from several vendors, including Compellent, Network Appliance and IBM.
"The IBM SAN didn't have the performance we needed; the NetApp wasn't cost-effective and the interface and usability wasn't easy, particularly when it came to training staff," says Croy. Compellent, he adds, was cost-effective, manageable and offered the performance Scott County needed.
Working with The Davenport Group, a St. Paul-based solution provider and Compellent channel partner, Scott County purchased and installed the Storage Center systems, each configured with 3TB of storage. One unit sits in the county's data center and the second in the disaster recovery site 14 miles away, which is connected by a dedicated cable between buildings.
"We replicate to the Storage Center at the disaster recovery site," says Croy.
Today, Scott County has six VMware ESX servers, and 95 percent of its Windows Servers, or 28, are virtualized or running in VMware with Compellent as the back-end storage.
"The ESX is attached to the disaster recovery site, so that in the case of a disaster, it will take us at 30 to 40 minutes max to recover our critical servers such as SQL, Exchange, WebSphere and Websense," says Croy. The county also takes snapshots on the file servers every four hours in case a file needs to be recovered.
Only changes are replicated to the disaster recovery site, or megabits every 30 seconds, he says. A bandwidth monitoring feature on Storage Center puts a limit on how much bandwidth will be used for replication. The county uses one gigabit speed during the day, while the system uses as much bandwidth as it needs during the night.
"This feature is particularly beneficial because it means we don't have to buy a big pipe," says Croy.
Scott County recently began utilizing the Storage Center solution for its development network. Croy says they take a point-in-time snapshot on the Storage Center server and the development network mimics the system at that point in time snapshot. "We have ESX virtual instances on the development network, so the folks in development can make changes and test them before we utilize them in our production environment," he says.
This allows Scott County to have a development network without having to add resources, something it wasn't able to do before. "Any upgrades we apply, we can do snapshots that we apply to the server and we can revert from bad changes if we need to," Croy says.
Scott County's IT department has 22 employees, 10 of whom work on infrastructure. They support almost 900 internal users.
Since installing Storage Center, the system has been upgraded twice. Today, each system has 7TB of storage, and plans are in place for another upgrade of 3-4 TBs for each server within the next six months.
Croy reports that the business units at the county continue to come up with new ways to use the new IT environment. For example, the county uses Storage Center as back-end storage, or virtual instance, for its document management system.
"We have a lot of records that we eventually need to move to make them more efficient, such as police data that sits on an AS/400 here at the data center and at the disaster recovery site," says Croy.